Crandall Canyon Mine Collapse Implicates MSHA Procedures
by Sam Kim, 8/20/2007
The Aug. 6 mine collapse at the Crandall Canyon coal mine in Utah, which trapped six coal miners and led to the deaths of three rescue workers, again calls into question the effectiveness of the federal Mine Safety and Health Administration (MSHA). The mine operators were working under a plan approved by MSHA in June, just months after serious structural problems forced the operators to abandon a work area only 900 feet from where the miners are trapped.
In March, miners were engaged in "retreat mining" — cutting out the pillars of coal supporting the mountain above the main tunnel and allowing the roof to collapse — when the northern tunnel experienced a shift of the ground, a "bump," that caused severe damage, according to an Aug. 12 article by The Salt Lake Tribune. Mine operators often use retreat mining to extract the last substantial deposits of coal before abandoning a mine area altogether.
According to a memo obtained by The Tribune, the mine operators knew the pressures from the 2,100 feet of mountain above the mine created the roof problems that caused them to abandon the northern tunnel. The operators, UtahAmerican Energy, Inc., hired a Colorado mining engineering firm, Agapito Associates, Inc., to help the operators determine a safer way of retreat mining the southern tunnel. The southern tunnel area is where the men are now trapped. Rescue efforts were suspended late Aug. 16 after three rescue workers were killed and six others injured by another collapse.
In late May, MSHA began inspecting the Crandall mine roof but the inspection was not completed by the time of the Aug. 6 collapse. In June, amidst the ongoing inspection, MSHA approved an amendment to the mining plan to allow retreat mining in the southern tunnel. To safely do this, Agapito recommended increasing the size of the coal pillars from 92 feet to 129 feet. According to The Tribune, it is not clear if the wider pillars were used. The Aug. 6 collapse registered as the equivalent of a 3.9 magnitude earthquake, according to seismology experts.
Robert Ferriter, director of the Colorado School of Mines and a 27-year veteran of MSHA, was highly critical of the decision to allow retreat mining in the southern tunnel. The conditions caused by the weight of the mountain above would not have been different from those in the northern tunnel 900 feet away, and that should have triggered a more cautious response from MSHA, he told The Tribune.
Others also criticized MSHA's approval of the plan amendment. Tony Oppegard, a former MSHA advisor and a Kentucky mining regulator, criticized the use of retreat mining at the Crandall mine given the conditions, according to another article by The Tribune. "Everyone understands that in the West you have tremendous pressures on those coal pillars from the overburden and they are subject to bursting," Oppegard reportedly said.
The Aug. 13 issue of Mine Safety and Health News reported that Dr. R. Larry Grayson, who heads the Pennsylvania State University mining and engineering program, agreed with Ferriter that he would not have approved retreat mining under the existing conditions at the Crandall mine. The mining company may have been following the MSHA-approved mining plan, but that does not mean that it was safe. "Generally speaking, most mines would not choose to mine pillars that lie between two extensive abandoned (mined out) areas," Grayson said.
Questions about MSHA's oversight at Crandall come on the heels of the 2006 Sago, Aracoma and Darby mine disasters. Nineteen miners died in these three incidents, and 47 miners died in all 2006 coal mining incidents, the highest number of fatalities since 2001, according to MSHA's statistics. Two House bills were introduced this congressional session to enhance the 2006 MINER Act passed in the wake of these incidents. To date, there have been 14 coal mining fatalities in 2007, not including the recent deaths in Utah.
On Aug. 20, rescue efforts at the Utah mine were called off indefinitely due to concern about the safety of rescue workers.
Mine Safety and Health News also reported that Utah Gov. Jon Huntsman, Jr. (R) expects the state to play a role in the investigation of the Crandall mine incident and hopes to expand the state's role in regulating worker safety. Huntsman wants to use the model employed by West Virginia Gov. Joe Machin (D) after the Sago incident. Machin hired former MSHA administrator J. Davitt McAteer to represent the state during the Sago investigation. Currently, miner safety is a federal responsibility once the miners go underground. The state has surface environmental and worker health responsibilities. Hunstman wants to explore changes to the limited state role.